Why you should never order ice on a plane

Steer clear of anything made with tap water on an airplane. Reuters/Kham

If you order ice on an airplane, there's a chance it could be riddled with bacteria.

Ice is typically made from the plane's supply of tap water, which is kept in tanks that have been found to breed bacteria.

Even flight attendants refuse to drink anything made with an aircraft's tap water.

There are plenty of things you should (and shouldn't) do to make sure your flight goes as smoothly as possible when you're traveling. One thing that should be at the top of your list of air travel don'ts? Ordering ice on the plane.

The opportunity for microbial growth is due in part to the fact that an aircraft's water tank is rarely emptied and cleaned. According to the study, tanks are only emptied and refilled when the plane is being serviced, when the water runs out on its own, or during the winter to prevent the tank from freezing.

The same study also found that long-haul flights have more bacteria than short-haul flights, and, according to NBC, EPA data from 2012 shows that one in 10 planes tested positive for carrying potentially harmful microbes in its water supply.